#12 先乘除後加減和考慮負數的計算機 App

程式碼:

import UIKit
enum CalculationType {
case add
case subtract
case multiply
case divide
case none
}
class ViewController: UIViewController {
var calculation : CalculationType = .none
var beforeNumbers = 0.0
var afterNumbers = 0.0
var startNew = true
@IBOutlet weak var displayLabel: UILabel!
override var preferredStatusBarStyle: UIStatusBarStyle {
return .lightContent
}
@IBAction func numbers(_ sender: UIButton) {
let inputNumbers = sender.tag — 1
if self.startNew == true {
self.displayLabel.text = “\(inputNumbers)”
self.startNew = false
}
else {
if self.displayLabel.text! == “0” || self.displayLabel.text! == “+” || self.displayLabel.text! == “-” || self.displayLabel.text! == “X” || self.displayLabel.text! == “/” {
self.displayLabel.text = “\(inputNumbers)”
}
else {
self.displayLabel.text = self.displayLabel.text! + “\(inputNumbers)”
}
}
self.afterNumbers = Double(self.displayLabel.text!)!
}
@IBAction func add(_ sender: UIButton) {
self.displayLabel.text = “+”
self.calculation = .add
self.beforeNumbers = self.afterNumbers
}
@IBAction func subtract(_ sender: UIButton) {
self.displayLabel.text = “-”
self.calculation = .subtract
self.beforeNumbers = self.afterNumbers
}
@IBAction func multiply(_ sender: UIButton) {
self.displayLabel.text = “X”
self.calculation = .multiply
self.beforeNumbers = self.afterNumbers
}
@IBAction func divide(_ sender: UIButton) {
self.displayLabel.text = “/”
self.calculation = .divide
self.beforeNumbers = self.afterNumbers
}
@IBAction func result(_ sender: UIButton) {
switch self.calculation {
case .add :
self.afterNumbers = self.beforeNumbers + self.afterNumbers
turnNumber(self.afterNumbers)
case .subtract :
self.afterNumbers = self.beforeNumbers — self.afterNumbers
turnNumber(self.afterNumbers)
case .multiply :
self.afterNumbers = self.beforeNumbers * self.afterNumbers
turnNumber(self.afterNumbers)
case .divide :
self.afterNumbers = self.beforeNumbers / self.afterNumbers
turnNumber(self.afterNumbers)
case .none :
self.displayLabel.text = “\(self.afterNumbers)”
}
self.startNew = true
}
@IBAction func clean(_ sender: UIButton) {
self.displayLabel.text = “0”
self.beforeNumbers = 0
self.afterNumbers = 0
self.calculation = .none
self.startNew = true
}
func turnNumber ( _ number : Double ) {
var okText : String
if floor(number) == number {
okText = “\(Int(number))”
}
else {
okText = “\(number)”
}
if okText.count >= 10 {
okText = String(okText.prefix(10))
}
self.displayLabel.text = okText
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
}

TingKai-Chen/Peter_Homework12